Acoustic drying system with matched exhaust flow

Abstract

An inkjet printing system, comprising: one or more inkjet printheads for printing drops of ink onto a receiver medium, and an acoustic air impingement drying system positioned in proximity to at least one of the inkjet printheads. The acoustic air impingement drying system includes: an airflow source providing a supply flow rate; an acoustic resonant chamber having an inlet slot that receives air from the airflow source and an outlet slot that directs air onto the receiver medium; an exhaust air channel for removing the air directed onto the receiver medium by the acoustic resonant chamber; a blower for pulling air through the exhaust air channel at an exhaust flow rate; and a blower controller that controls the supply flow rate and the exhaust flow rate, wherein the exhaust flow rate is controlled to match the supply flow rate to within 1%, or to exceed the supply flow rate.

The invention claimed is: 
     
       1. An inkjet printing system, comprising:
 one or more inkjet printheads, each having an array of ink nozzles for printing drops of ink onto a receiver medium; 
 a receiver media transport system for moving the receiver medium past the inkjet printheads; and 
 an acoustic air impingement drying system positioned in proximity to at least one of the inkjet printheads, the acoustic air impingement drying system including:
 an airflow source providing air at a supply flow rate; 
 an acoustic resonant chamber having an inlet slot that receives air from the airflow source and an outlet slot that directs air onto the receiver medium, wherein the acoustic resonant chamber imparts acoustic energy to the air flowing through the acoustic resonant chamber; 
 an exhaust air channel for removing the air directed onto the receiver medium by the acoustic resonant chamber; 
 a blower for pulling air through the exhaust air channel at an exhaust flow rate; and 
 a blower controller that controls the exhaust flow rate, wherein the exhaust flow rate is controlled to match the supply flow rate to within 1%, or to exceed the supply flow rate, and 
 
 wherein the acoustic resonant chamber includes a plurality of closed-end resonant chambers. 
 
     
     
       2. The inkjet printing system of  claim 1  wherein the blower controller also controls the supply flow rate, the supply flow rate being controlled by sensing the supply flow rate and adjusting the supply flow rate when a difference between the sensed supply flow rate and a predefined aim supply flow rate exceeds a predefined threshold, and the exhaust flow rate being controlled by sensing the exhaust flow rate, and adjusting the exhaust flow rate when a difference between the sensed exhaust flow rate and a predefined aim exhaust flow rate exceeds a predefined threshold, the aim exhaust flow rate being greater than or equal to the aim supply flow rate. 
     
     
       3. The inkjet printing system of  claim 1  wherein the exhaust flow rate is controlled by sensing the supply flow rate and the exhaust flow rate, and adjusting the exhaust flow rate when a difference between the sensed supply flow rate and the sensed exhaust flow rate exceeds a predefined threshold. 
     
     
       4. The inkjet printing system of  claim 1  wherein the exhaust flow rate is controlled by sensing an airflow rate at a position intermediate to the acoustic air impingement drying system and one of the inkjet printheads. 
     
     
       5. The inkjet printing system of  claim 1  wherein the outlet slot of the acoustic air impingement drying system is positioned no more than 45 mm from the ink nozzles in the nearest inkjet printhead. 
     
     
       6. The inkjet printing system of  claim 1  wherein the acoustic resonant chamber is positioned between two inkjet printheads. 
     
     
       7. The inkjet printing system of  claim 1  wherein the exhaust air channel removes air from at least two sides of the outlet slot. 
     
     
       8. The inkjet printing system of  claim 1  wherein the acoustic air impingement drying system includes a plurality of output slots, each output slot directing air onto the receiver medium and being oriented at an oblique angle relative to the direction of receiver medium movement.